So the article doesnt say if any of his promotions were revoked. If they werent, when he joined he was part of the High 3 plan. This plan would take your last 36 months, and divide it by 36 to compute your retirement pay. If promotions were not revoked and he retired immediately, his retirement pay would pretty much be for an E9, since he could have 34 or 35 months of E9 pay and only 1 or 2 months of E5 pay.